Thirsty Concrete Goes Viral

What are the odds more than 500,000 people would watch a YouTube video of truck dumping water on a parking lot? OK, the odds are good, all Internet things considered. But what they saw is pretty amazing. More after the video.

The thirsty surface you just watched (and perhaps watched again) is called Topmix Permeable, a product of Tarmac, a UK company. Tarmac describes it as:

[A] fast draining concrete pavement solution that rapidly directs stormwater off streets, parking surfaces, driveways and walkways. This minimises the cost and long-term maintenance for local authorities and developers of stormwater management.

There are immediate questions, of course. One waggy viewer asked if it was safe to walk on Topmix Permeable, given humans are up to 75% water. More seriously, how will it behave in the notoriously tough winters of Potsdam, NY?

According to the company, the same voids that allow the fast drainage “speed up snow and ice thawing.” But durability is an equal concern, given expanding ice likes to erode and enlarge fissures and cracks, and once in place may not thaw for months. The specs are not as clear on weather extremes.

Neither is the company explicit about whether the product is contaminant free. And, of course, the condition of highways and parking lots becomes a major consideration — a fast draining surface that sends water directly into the ground is one where central collection and subsequent treatment for gasoline, oil and other contaminants is unlikely.

By The National Guard (Uploaded by Dough4872) [ CC BY 2.0 ],  via Wikimedia Commons

By The National Guard (Uploaded by Dough4872) [CC BY 2.0], via Wikimedia Commons

But if Topmix Permeable is durable, inert, manageable and weather resistant, the benefits are many, especially here in New York State where urban heat islands, regular flooding of highways and stormwater runoff are major problems created by impermeable surfaces. Prolonged coastal floods is another. Superstorm Sandy left deep, standing water for days in cities and neighborhoods all along the East Coast. The impermeable surfaces of populated communities in effect created acres of impromptu ponds that caused long term flood damage, trapped cars, and overwhelmed storm sewers.

As have many companies, Tarmac is also using climate change as a selling point:

The built environment has grown rapidly over the last 50 years, resulting in large areas of land being paved over with impermeable materials . . . With climate change predicted to lead to increasingly warmer and wetter weather conditions, rainfall is likely to continue to rise.